I'd actually quite like the Audi if it didn't have the stupid little plastic air-scoop on the top. The old Quattro grille has been blended into the new shape really well.
Still not the point though, having something that large would not be good for the brakes if they were ever used hard and got hot. Brakes are not cooled purely from the inside of the hub, they also draw in air from the outside of the wheel, yet they are not able to due to that huge contraption.
Yes, pretty much every car on the market now has a dust sheild, but they look like this.
All I'm going to say is: For normal street driving you will NEVER notice a difference with or without brake dust shields on the car. Except that without them your wheel get dirty